Zana map w/ corrupted mobs and fracture

Zana daily quest, kill the corrupted monsters in the time limit, touching stones increases the limit. Map was fracturing sea witches with frenzy charges, all was well, except that when I killed the corrupted monsters, not only did the count killed go up, but the count I had to kill went up...

This happened to me once as well except it was in a map where killing monsters increased the time limit. By the time I finished I had 40 minutes left on the clock.

Just had the same thing as op, zana quest kill corrupted monsters in the time limit sandstones increase the time. Map mods were seawitches, frenzy charges, monsters fracture. I had maybe 5 sandstones in a 73 academy. started with 1:30 on the clock and like 100 monsters to kill, by the time my time ran out i had killed 490 corrupted monsters and needed to kill 580 or something. Anyone know if this is a bug or what? pretty annoying

It's not a bug. So, you have 1 corrupted monster. When you kill it, it fractures into several more corrupted monsters. Look at the number when you start the map. That's how many original monsters you have to kill. For each one of them, when you make it fracture, the number will go up by how many monsters it fractured into.